The entrance to your underground home is probably the most important part- at least, the part that it’s most important to be careful with.
In most cases, the entrance is the only part of your subterranean lair that anyone’s going to look at with any frequency- so it makes sense to very carefully make it either solid and pleasing to look at, or very very difficult to locate.
It’s also a good idea to dig it into stone instead of dirt.
Dirt is immensely less durable than stone- and usually far less pleasing to look at.
If you’re notably concerned with the appearance of your entrance, chances are you’re either on a grief-proofed multiplayer server or playing a single-player game where you want to take screenshots or videos to show other people. In these cases, go ahead and make your entrance ostentatious. Fabricate stone pillars or even a whole gazebo or Roman-style temple building around the entrance to your home. If you’ve dug into the side of a mountain, this can look especially pretty, as you can lay out a broad stairway up to a sheltered entrance, perhaps with a low cobble wall around the whole thing and a small ‘front yard’ garden. You might want to make it impressive in a different way- carving off a layer from the mountain face can let you build a mural around your front door, or fortify it like an ancient castle with towers and a high wall- perhaps with stairs leading up to the parapets.
Perhaps you want to go the other way? A gravel walkway up to a simple door can be pleasing, especially with a small porch or even just a little overhang to protect the doorway from occasional rain. A small wooden palisade with a door in it as well can be nice and simple to look at, or perhaps digging out a small inset around your front door.
If your entrance is a pit dug into the ground, you can overlay the shaft with glass, allowing people to stand ‘on’ your front door and look down to see if you’re home. You can erect a free-standing building over the pit, marking your home with a pleasant touch if you like. Perhaps you’ve got a downwards stairway into your home from the surface- a ‘mud hut’ built out of dirt can look pleasantly natural. Or you could dig it into the side of a small hill in a sandy area, and hang a sign above your door that reads ‘Sander’s End’.
If you’re on a server where griefing is a risk, though, you can get a lot from hiding the entrance to your home. Trees or bushes can provide obscurity, and digging a single-block shaft beneath one with a simple trap door over it can keep your home safe. Building your home into a mountainside and using a waterfall to climb up into it can let you ‘take up’ your door when you’re inside, requiring intruders to build themselves a stairway or dig through most of a mountain- more trouble than most griefers will go to- they’re after easy chuckles. If you want to be especially tricky, you can devise a way to start digging your home into the ground from the middle of the ocean, or the bottom of a lake- a trapdoor will let you keep the water out once you’re inside your home.
However you do it, though, keep in mind that if you let anyone into your home, your entrance is going to set their expectations for the style of the home itself- a simple entrance best fits a simple home, and the same for a fancy front door and a complex or highly beautified home.
